1. Field of the Invention
The present invention generally relates to a remote resource management system for maintaining remote resources in a distributed computing environment. More specifically, the present invention relates to a remote resource management system for maintaining remote resources downloadable to terminal computers, which are typically personal computers, in a distributed heterogeneous computing environment where a plurality of platforms for different applications are interconnected by a public telecommunications service or a local area network (LAN).
2. Description of the Related Art
Unlike stand-alone systems, terminal computers working in a network computing environment need not have all software and data resources in their local storage. Instead, they can download such resources from a server computer via a network, when a specific application is requested.
Assume here that a user has a video data file, for example, and he/she is attempting to play it on his terminal computer. The video requires a movie player program of a certain version or later, but the terminal computer may not have such a program or, even if the computer has one, the version of the movie player program may be too old to support the data format of that video data file. If this is the case, the terminal computer will download the required movie player program from an appropriate server before playing the video.
As illustrated above, terminal computers in a distributed environment can share some software resources and/or data resources, which are referred to as downloadable resources. Such downloadable resources, however, must be managed and maintained in a proper way to ensure reliable operations in the terminal computers.
FIG. 12 shows an example of a conventional management system for shared software resources. In this example, a network N101 interconnects a server computer A101 and three terminal computers T101, T102, and T103, thereby forming a distributed computing system. The server computer A101 has downloadable resource storage D101 to hold downloadable resources and a downloadable resource directory B101 to manage the resources. Specifically, the downloadable resource storage D101 stores three resources F101, F102, and F103 in separate files.
Those resource files are classified into groups according to their respective usage in the terminal computers T101-T103. In this example, the resource F101 belongs to a resource group G1, while the other resources F102 and F103 belong to a resource group G2.
The downloadable resource directory B101 manages the relationship between the terminal computers and the resources available in the downloadable resource storage D101. As noted in FIG. 12, the downloadable resource directory B101 defines that the group-G1 resource is destined for the terminal computer T101, and that the group-G2 resources are for the terminal computers T102 and T103.
In one type of operation, the server computer A101 takes the initiative in downloading the resources. The server computer A101 first sets up a logical connection to each of the terminal computers T101-T103, and then transfers the resource files F101-F103 to them according to the terminal-resource relationships which are registered in the downloadable resource directory B101. That is, the resource file F101 belonging to the resource group G1 is downloaded to the terminal computer T101, while the resource files F102 and F103 belonging to the resource group G2 are delivered together to the terminal computers T102 and T103.
In another type of operation, each terminal computer takes the initiative in downloading resource files. For example, the terminal computers T101, T102, and T103 establish a logical connection to the server computer A101 upon their power-up, and independently download the resource files F101-F103 from the server computer A101 according to the downloadable resource directory B101.
In the above-described distributed computing system, however, the resource group definition registered in the downloadable resource directory B101 may include some files that are not immediately necessary for a terminal computer. Downloading of resource files including such unnecessary ones can impact the storage capacity of a local hard disk in the terminal computer, as well as consuming much time to transfer a large amount of data. Since data resources for multimedia applications are generally large in size, such concentrated downloading of a predefined group of multimedia data files is particularly time-consuming and storage-intensive.
FIG. 13 shows another example of a conventional remote resource management system. In this system, a server computer A111 working as a file server and a plurality of terminal computers, say, three terminal computers T111, T112, and T113 are interconnected by a network N111. The server computer A111 has downloadable resource storage D111, where all resources F111, F112, and so on are collected.
Upon demand, the terminal computers T111, T112, and T113 download necessary resources selected from among the resources F111, F112, and so on, which are stored in the server computer A111 as the common resources. The server computer A111 is maintained by a system operator who reloads necessary resource files when some programs should be updated.
On the terminal side, however, there is no such specialist or management mechanism responsible for maintenance of the downloadable resources. Therefore, each terminal user must maintain the local resources by downloading new program files individually from the server to his/her own terminal computer, when it becomes necessary. That is, the latest resource files in the server computer are not automatically delivered to the terminal computers. In the case that some resources are updated quite often, the terminal users are frequently requested to maintain the versions of such resources. Frequent update of those downloadable resources will force the terminal users to spend much time for reinstallation of them.